Critics praised bad-girl British artist Tracey Emin’s 1998 furniture-and-effects exhibit, “My Bed,” supposedly representing a failed romantic relationship, featuring mussed sheets and, around the room, empty vodka bottles and used condoms. Prominent collector Charles Saatchi turned heads when he bought the piece for about $200,000. In June, almost 15 years later, he sold “My Bed” at auction for $4,330,000.